This invention relates generally to pallet dispensing machines and in particular to a new and novel pallet dispensing machine that can handle the different types of pallets available on the market as well as deformed, or out of shape, used pallets that would cause trouble in prior art types of machines.
In the feeding of wooden or plastic pallets to a downstream operation, it is known in the prior art to use hydraulic rams to shove the bottom pallet from a stack of 10 to 12 pallets positioned above in a stationary frame. Such pallet dispensers use brute force to move the bottom pallet against the entire load of the pallets stacked on top. This type of dispensing can cause damage to the pallets, especially when some or all of the pallets are used or deformed with warped boards.
Another type of prior art pallet dispenser uses air operated pallet fingers to hold the stack of pallets up while a hydraulic ram pushes the lower pallet to the downstream conveyor. Deformed pallets also can cause extensive trouble in these prior art dispensers. Both of the above described prior art machines also require extensive floor space on one side of the dispenser for the hydraulic ram mechanism to operate to extend out and back in pushing the bottom pallet out of the stack.
The most common type of prior art pallet dispensers use a twin fork mechanism that is positioned on one side of the pallet dispenser to insert into the penultimate pallet to lift the entire stack up while the bottom pallet is moved out to a downstream position. Large air or hydraulic cylinders are used to accomplish the lifting with various chains and gears being used to create the motions to accomplish the multidirectional move. Such a complicated system also requires large floor space to accommodate the motion of the twin forks as well as extensive safety guards around the complicated machinery. Since the normal number of pallets can range from 10 to 12 in the stack, and pallets can range in weight from 35 to 170 pounds, it can be seen how this type prior art pallet dispenser can have problems due to the large load on the twin forks which must be lifted by cantilevered twin forks. Sag in the forks is a common problem when lifting the heavier pallets and maintenance can be high on this type of dispenser due to the complicated motion needed to accomplish the lifting.
While all of the before described prior art dispensers have been used before with varying results, each type has its own particular problems that make the pallet dispenser far from perfect.